Diet or regular? Decoding behavioral variation in ant clones

The ant species Strumigenys membranifera used in the experiments. Credit: Eisuke Hasegawa.

Clonal ants appear to be diverse in responding to sweetened water, suggesting epigenetic regulation in behavioral variation and colony survival.

Ants - Show - Diversity - Attraction - Sweetness

Genetically identical 'clonal ants' show surprising diversity in their attraction to sweetness, according to new research in the journal Royal Society Open Science. While differences in behavior and preferences among a species are usually attributed to genetic variation, the cause of multiple 'phenotypes' is less clear-cut for ants that are identical clones.

Colonies of some ant species such as Strumigenys membranifera reproduce by asexually cloning themselves, so have the same genes, with the exception of random mutations. Thus, their reactions to sweetened water should be the same if determined from birth.

Ecologist - Eisuke - Hasegawa - Hokkaido - University

Ecologist Eisuke Hasegawa of Hokkaido University and colleagues tested how strong a sucrose solution had to be to get individual ants to drink it within one minute of detection. This indicated the ants' 'response threshold'. They found significant variation between 82 workers from two groups of cloned ants. Some preferred a 1% sugar solution - the equivalent of diet soda, while others wouldn't drink until it reached 10% - more like a regular soda.

The team had three hypotheses: that the threshold could be set during the larval stage and remain unchanged; it could increase or decrease in one direction with age; or it could be randomly determined by external factors during adulthood.